A robotic tool changer removably attaches a robotic tool to a robotic arm. The changer includes a tool module connected to the robotic tool, and a master module connected to the robotic arm. To attach and detach the robotic tool, the changer couples and uncouples the tool module and the master module. A master electrical signal module (ESM) affixes to the master module and a tool ESM affixes to the tool module. In accordance with design requirements, the changer applies the same power supply to both the master ESM and the tool ESM. The changer, however, selectively suppresses application of the power supply to the tool ESM, while maintaining application of the power supply to the master ESM, during the coupling or uncoupling of the master module and the tool module. In doing so, the changer enables such coupling and uncoupling, while also preventing the formation of transient electric arcs.